Meat is an important edible postmortem component originating from food animals. The increasing demand for animal proteins like meat and meat products has increased load of slaughter houses, resulting in inadequate attention being paid to the hygienic aspect of meat production. During the process of converting live food animal into meat, microbial contamination of carcass is unavoidable. During the process of dehiding, evisceration, cutting, packing, etc., meat is exposed to various environmental contaminants which may be from diseased animal, unhygienic environment, unhygienic butchering habits, faulty slaughter procedures, post slaughter handling and storage (Mawia et al., 2012). In India, temperature and humidity are ideal for growth and survival of microorganisms. Hot climate and lack of proper storage facilities, render meat, vulnerable to spoilage, thus, posing risk to consumers (Chaubey et al., 2004). Cross contamination occurs during handling of raw meat especially poultry meat, due to presence of more liquid in raw meat.

Contamination of meat with food borne pathogens remains an important public health issue, as it can lead to illness resulting human suffering and loss of productivity and significantly to the cost of health care. Raw meat may harbor many important pathogenic microbes such as E. coli, S. aureus, Campylobacter, Salmonella, Listeria etc., that causes risk to the human health (Mead et al., 1999). Poultry meat is more popular in India due to cheaper cost, accepted by many classes, easily available and good digestibility (Yashoda et al., 2001). If microbial contamination exceeds certain levels, it adversity affects Shelf life and renders the meat unfit for human consumption (Fasanmi et al., 2010). As per guidelines stipulated to ensure safe meat handling by World Health Organisation (WHO), Food and Agriculture Organisation (FAO) and Codex Alimentarius Commission, Hazard Analysis Critical Control Point (HACCP) and Good Manufacturing Practices (GMP) plays important role (Hassan Ali et al., 2010).

In India the retail sale of meat is not organised and the conditions in meat shops is not up to the satisfactory level which may lead to enhancement of microbial contamination. Much work has not been conducted about the microbial quality of various varieties of meat in and around Greater Hyderabad Municipal Corporation (GHMC), hence this study was undertaken.

Materials and Methods

30 each of mutton, chevon, chicken and pork samples (50gms) were collected from meat retail shops from different geographical areas in and around Greater Hyderabad Municipal Corporation (GHMC), packed in self sealed sterile polyethylene bags, kept in thermocool box with ice and transported to the laboratory of Veterinary Public Health, College of Veterinary Science, Rajendranagar, Hyderabad and stored at -20 °C till further examination.

Boiling Test

Small piece of meat sample was added into a test tube to which 10 ml of water was added, closed tightly with cotton plug and boiled. The cotton plug was taken out and the steam vapour was smelled to evaluate possible abnormal orders in carcasses.

Malachite Green Test

6 grams of meat sample was taken in a conical flask then 14 ml of distilled water was added to it and was allowed to stand for 15 minutes. The sediment formed was removed and 0.7ml of extract was taken into test tube containing a drop of malachite green and a drop of hydrogen peroxide and then shaken the mixture until it foams. It was allowed to stand for 20 minutes, clear and blue color liquid indicates good quality, cloudy and green color liquid indicates moderate quality, cloudy and olive green color liquid indicates bad quality meat.

Nitrazine Yellow Test

Small quantity of sample was taken in petri dish, Nitrazine yellow indicator was added to it then colour change was observed. Yellow colour indicates good quality (Ph-6.0), Olive green indicates moderate quality (Ph-6.4) and bluish violet indicates bad quality (Ph-6.8).

Microbiological Analysis

10 grams of meat sample was added in 90 ml sterile distilled water or 0.1% peptone water and was homogenized in a stomacher, which gives 1:10 dilution.1 ml from first dilution (101) was transferred to second test tube and so on containing 9ml to give 1:100, 1:1000, 1:10000, 1:100000 dilution.1 ml from appropriate dilution was transferred into sterile petri dish and10-15ml of nutrient agar was added for Total viable count (TVC) , Mac conkey for coliforms and faecal coliforms, Sabouraud Dextrose Agar (SDA) for yeast and molds. The plates were inverted and incubated at 37°C for TVC, coliforms and 44.5oc for faecal coliforms. The incubation period is 24 to 28 hours for all except 4-5 days for yeast and molds.

Isolation and Enumeration of Pathogenic Microorganism

For isolation of Escherichia coli, Salmonella spp and staphylococcus aureus EMB agar, XLD agar and MSA agar were used respectively, and counts were made on these media using appropriate dilution of the samples.

Results and Discussion

Physiochemical Evaluation

Boiling test, Nitrazine yellow test and Malachite green test results were presented in Table 1. Based on boiling test chevon (100%), mutton (66.7%), chicken (83.3%) and pork (53.3%) samples were of good quality. This test is an index for abnormal odours. Chevon (50%), mutton (66.7%) and chicken (50%) were good based on Nitrazine yellow test, whereas all the samples of pork, 50% of chevon and chicken and 33.3% of mutton were of moderate quality. None of the samples are bad. This test indicates the developed alkalinity due to decomposition of meat. Based on Malachite green test 50% of chevon were moderate quality, where as 26.7% and 23.3% were good and bad quality respectively. 33.3 % of each mutton samples were good, moderate and bad quality respectively, whereas 76.7% of chicken and 73.3% of pork were good quality and remaining are moderate quality. None of the chicken and pork samples are bad.

Table 1: Quality of meat samples

S. No

Type of Meat

Boiling Test

Nitrazine Yellow Test

Malachite Green

Good quality

Bad quality

Good

Moderate

Bad

Good

Moderate

Bad

1

Chevon 30

30 (100%)

0 (0%)

15 (50%)

15 (50%)

0 (0%)

8 (26.70%)

15 (50%)

7 (23.30%)

2

Mutton 30

20 (66.70%)

10 (33.30%)

20 (66.70%)

10 (33.30%)

0 (0%)

10 (33.40%)

10 (33.30%)

10 (33.30%)

3

Chicken 30

25 (83.30%)

5 (16.70%)

15 (50%)

15 (50%)

0 (0%)

23 (76.70%)

7 (23.30%)

0 (0%)

4

Pork 30

16 (53.30%)

14 (46.70%)

0 (0%)

30 (100%)

0 (0%)

22 (73.30%)

8 (26.70%)

0 (0%)

Total samples = 30

Fig. 1: Boiling Test

Microbiological Quality

Total viable count, coliforms, faecal coliforms, yeast and mold counts of the meat samples are presented in Table 2.

Table 2: Microbial counts in various meat samples (CFU per gram)

S. No.

Types of Meat

TVC

Coliforms

Faecal Coliforms

Yeast and Molds

1

Chevon

6.51 log10

3.81 log10

2.68 log10

58

2

Mutton

2.55 log10

3.82 log10

5.71 log10

34

3

Chicken

4.85 log10

6.58 log10

2.1 log10

42

4

Pork

4.15 log10

3.68 log10

4.2 log10

62

The total viable count in Chevon samples was 6.51 log10CFU/gm in the present study, which was less than the counts of 6.62 log10CFU/cm2reported by Ahmad et al. (2013), higher than the counts of 6.37 reported by Mawia et al. (2012) and in the range of the counts of 4.09 to 6.79 log10 CFU/cm2reported by Feizullah and Daskalov (2010). The total viable count in mutton samples was 2.55 log10CFU/gm in the present study, which was less than the counts of 6.92 log10 CFU /cm2 and 4.32 to 7.2 log10 CFU/gm reported by Ahmad et al. (2013) and Feizullah and Daskalov (2010) respectively and higher than the counts of 2.4 log10 CFU/cm2 reported by Bass et al. (2011). The total viable count in chicken samples was 4.85 log10CFU/gm in the present study, which was less than the counts of 7.22 log10CFU/cm2and 6.82 log10 reported by Ahmad et al. (2013) and Singh et al. (2014). The total viable count in pork samples was 4.15log10CFU/gm in the present study, which was less than the counts of 7.78 log10 CFU/g reported by Lambey et al. (2009). The coliforms count in mutton samples was 3.82 log10CFU/gm in the present study, which was higher than the counts of 2.78 log10CFU/cm2 reported by Ahmad et al. (2013).

Fig. 2: Nitrazine Yellow Test

In Chevon sample the coliforms count was 3.81 log10CFU/gm in the present study, which was higher than the counts of 2.74log10CFU/cm2 reported by Ahmad et al. (2013). In chicken sample the coliforms count was 6.58 log10CFU/gm in the present study, which was higher than the counts of 1.94 log10CFU/cm2reported by Ahmad et al. (2013).The coliforms count in pork was 3.68 log10 CFU/gm in the present study which was lower than the counts of 4.29 log10 CFU/gm reported by Lambey et al. (2009).

The incidence of certain pathogenic microorganisms in different meat samples was presented in Table 3. The incidence of E. coli in mutton samples was 60% in the present study, which was higher than the incidence (55%) and (49%) reported by Ahmad et al. (2013) and Yadav et al. (2006) respectively and less than the incidence (96%) reported by Sharma et al. (2015). The incidence of E. coli in chevon sample was 73.3% in the present study, which was higher than the incidence (50%) reported by Ahmad et al. (2013) and less than the incidence (83.3%) reported by Rathod et al. (2004) .The incidence of E. coli in chicken sample was 90% in the present study, which was higher than the incidence (48%)and (39.5%)reported by Ahmad et al. (2013) and Vorster et al. (1994)respectively and less than the incidence (100%) reported by Sharma et al. (2015).The incidence of E. coli in the pork sample was 86.7% in the present study.

The incidence of Salmonella spp in Mutton sample was 43.3% in the present study, which was higher than the incidence of 2%, 3% and 10% reported by Sharma et al. (2015), Yadav et al. (2006) and Ahmad et al. (2013) respectively. The incidence of Salmonella spp in Chevon sample was 56.7% in the present study, which was higher than the incidence (10%) reported by Ahmad et al. (2013). The incidence of Salmonella spp in chicken sample was 100% in the present study, which was higher than the incidence 2% and 25% reported by Sharma et al. (2015) and Ahmad et al. (2013) respectively. The incidence of Salmonella spp in pork sample was 73.3% in the present study.

Fig. 4: Incidence of pathogenic microbes in samples

The incidence of Staphylococcus spp in mutton samples was 86.7% in the present study, which was higher than the incidence of 18%, 68.6% and 45% reported by Sharma et al. (2015), Kumar et al. (2001) and Ahmad et al. (2013) respectively. The incidence of Staphylococcus spp in Chevon sample was 100% in the present study, which was higher than the incidence (70%) reported by Ahmad et al. (2013) and similar to 100% reported by Rathod et al. (2004) .The incidence of Staphylococcus spp in chicken sample was 90% in the present study, which was higher than the incidence of 22%, 23.4% & 55% reported by Sharma et. al. (2015), Vorster et al. (1994) and Ahmad et al. (2013) respectively. The incidence of Staphylococcus spp in pork samples was 100% in the present study.

Conclusion

On the basis of physical quality test (boiling test, nitrazine yellow & malachite green test) chevon and chicken were of good quality whereas, mutton & pork moderate to good quality. The microbiological quality of different meats based on total viable count (TVC), coliforms, faecal coliforms and yeast & mold counts were far above the standards specified under FSSAI 2011. Presently, the quality of meat sold in various markets were of inferior quality. Necessary steps should be taken to improve the quality by maintaining hygienic measures at all stages.